title: The effects of nicotine on cone and rod b-wave responses in larval zebrafish.
abstract: Acetylcholine is present in and released from starburst amacrine cells in the inner plexiform layer (IPL), but its role in retinal function except, perhaps, in early development, is unclear. Nicotinic acetylcholine receptors are thought to be present on ganglion, amacrine, and bipolar cell processes in the IPL, and it is known that acetylcholine increases the spontaneous and light-evoked responses of retinal ganglion cells. The effects of acetylcholine on bipolar cells are not known, and here we report the effects of nicotine on the b-wave of the electroretinogram in larval zebrafish. The b-wave originates mainly from ON-bipolar cells, and the larval zebrafish retina is cone-dominated. Only small rod responses can be elicited with dim lights in wild-type larval zebrafish retinas, but rod responses can be recorded over a range of intensities in a mutant ( n o optokinetic response f ) fi sh that has no cone function. We fi nd that nicotine strongly enhances cone-driven b-wave response amplitudes but depresses rod driven b-wave response amplitudes without, however, affecting rod- or cone-driven b-wave light sensitivity.
authors.affiliation: Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts.
authors.forename: Miguel
authors.initials: M
authors.lastname: Moyano
authors.forename: Angel
authors.initials: A
authors.lastname: Porteros
authors.forename: John E
authors.initials: JE
authors.lastname: Dowling
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology / Q000502:physiology; D000818:Animals; D003623:Dark Adaptation / Q000502:physiology; D004307:Dose-Response Relationship, Radiation; D004596:Electroretinography; D007814:Larva; D009154:Mutation / Q000235:genetics / Q000502:physiology; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D017120:Nystagmus, Optokinetic / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000235:genetics; D051245:Retinal Bipolar Cells / Q000187:drug effects; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects*; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects*; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*
chemical_list: D018722:Nicotinic Agonists; D011978:Receptors, Nicotinic; D009538:Nicotine; D000109:Acetylcholine